To test the hypothesis that ethnic differences may exist in the epidemiology of atrial fibrillation (AF) and other cardiovascular conditions among patients admitted to the hospital with nonhemorrhagic stroke, we reviewed registry data over a 2-year period of 832 consecutive patients admitted with nonhemorrhagic stroke to our hospital, which serves a multiethnic population. Indo-Asians and Afro-Caribbeans with acute (nonhemorrhagic) stroke had a lower prevalence of AF, despite a greater prevalence of diabetes and hypertension, than whites. AF was an independent predictor of increased mortality after stroke in our multiethnic population as a whole, but AF appears to be a less prominent factor in stroke among Indo-Asians and Afro-Caribbeans than in whites.